Strike plate gauge



Flcio.

`April 27,` 1943 J. M. JOHNSON STRIKE PLATE GAUGES Filedqune 11, 1942Patented Apr. 27, 1943 UN-lT'ED STATES PATENT GFFIICE STRIKE PLATE`GAUGE Jacob M. Johnson, Fargo, N. Dak.

Application June 11, 194.2, Serial No. 446,583

l Claim.

This invention relates to gauges for correctly locating a lock strikeplate upon a door jamb. The main object of the invention is to provide arelatively simple and practical device for quickly and correctlylocating such strike plate on a door jamb and marking the outlinesthereof for mortising the jamb to receive the plate in proper alignmentwith the lock bolts.

A preferred embodiment of the invention is shown in the accompanyingdrawing, wherein:

Figure 1 is a perspective View of the gauge, constructed in accordancewith this invention.

Figure 2 is a sectional detail on the line 2--2 of Figure 1.

Figure 3 is a section cn the line ure 1.

Figure 4 is a section on the line of 'f ure 1.

Figure 5 is a section on the line ure 1, v

Figure 5 is a top plan view of the gauge, on a reduced scale, showingalso a conventional 'strike plate mounted thereon for gauging the same,this constituting the iirst step in the operation of mounting the plateon the door jarnb.

Figure 7 is a plan View of the gauge asapplied upon a door and a bolt ofthe lock thereof, for gauging the space lbetween the bolt and inner iaceof the door, and for setting the scribepoints at opposite end of thegauge for marking the iocation of the strike plate. A fragmentary'Section ci the door is here shown. This view illustrates the secondstep of operation.

Figure 8 shows an edge View of the gauge and 3-3 of Fig- -a face view ofthe edge of the door, illustrating the application of the gauge to thedoor and lock bolt, as shown in Figure "I,

AFigure 9 is a face View of the gauge as applied at its scribing end tothe jamb of the door frame preparatory to marking the lateral limits ofthe strike plate on the jamb, this constituting the third step ofoperation. A fragment of the jamb is shown.

Figure 10 is an edge View of the gauge and a fragmentary sectional Viewof the jamb, according to the view of Figure 9.

Figure 11 is an enlarged sectional detail on the line II-II of Figure 9.

In practising the invention I provide an oblong base plate 5, includinga flat bottom B formed with raised lateral margins or guide rails 1extend in parallel relation and undercut or grooved at 8 from end toend. The rear end of the plate 5 is turned up and over inwardly inspaced relation above the bottom B to form a screw receiving lip 9, andthe forward end is turned up perpendicularly to provide a stop lip IIJ.

An elongated work slot I I is formed in the bottom 6 at one sidethereof, the same extending from a medial point of the bottom andopening out through the forward end, and including a recess or portl Ilacut through the stop lip I0. The margins of this slot are parallel witheach other and with the guide rails l.

A laterally elongated slot I2 is cut through the upturned rear lip 9immediately above the bottom S, and three elongated gauge strips orslides I3, I4, I5, of equal width and approximately equal length witheach other and the base plate 5, are slidably inserted side by .sidethrough the slot I2 and within the space between the guide rails 'I, thewidth of the said gauge-strips being such as to nicely ll the spacebetween the rails T. The lateral margins of the slides I3, Ill, I5, aregrooved vand feathered or splined, as shown at Iii, I'I, so as to nicelydovetail together or intermesh in slidable interengagement with eachother and with the lateral grooves 8 ci the rails l, thus holding theseelements all nicely and slidably interlocked.

Work lugs I8, IS, 2i] are seated in the upper sides of the forward endsof the slides I3, I4, I5. The lugs I9, 2li of the slides I4, I5, areextended or offset laterally toward one another, in mutual overlappingrelation and in longitudinal alignment (see Figs. 1 and 7), and the lug2!! is dimensioned to pass fully into the recess or port IIa, flush withthe stop lip Ill. A stop screw 2| in the rear end of the slide I5 abutsthe lip Il, as the slide is pushed in, simultaneously as the lug 2lienters the recess Ila, thus limiting further movement forward of thisslide. Sharpened scribing lugs 22, 23, are seated in the under sides ofythe forward ends of the slides I4, I5, beneath the lugs I9, 20, and arepositioned to work in longitudinal alignment through the slot Il (seeFig. 11) These scribing lugs project through the bottom 6 (see Figs. 8,10, 11), and are oiset towards one another relative to their respectivework lugs I9, 20, so that their points are aligned with the inner oradjacent faces of the work lugs i9, 20. Thus the lateral dimension of astrike plate 24 (Fig. 6) held snugly between the lugs I9, 2li, may beexactly marked upon a door jamb 25 by pressing the points into the jamband moving the device vertically.

A two-way work lug 26 is rigidly and perpendicularly mounted at the rearend of the slide I3, and a scale of measure calibrations 21 are stampedupon the face of the slide inwardly of the lug 26 and so as to measurethe space be tween the inner side of that lug and the adjacent corner 9aof the lip 9. Thus by placing this corner 9a against the closing or stopmargin of a door 28, and then drawing out the measure slide I3 andplacing the stop 26 snugly at the flat side of the lock bolt 29, thespace subtended will be indicated on the scale 21.

A boss 30 is seated medially on the turned lip 9, and this boss and lipare tapped to receive a knurled thumb-screw or center slide lock screw3| turned down therethrough'. An elongated press spring or clip 32 ofthin spring metal, folded length-wise upon itself and thus U-shaped incross-section, is inserted, bight innermost, between the over-turned lip9 and the rear ends of the slides I3, I4, I5, the stem of the screw 3|being passed freely and medially through the upper leaf thereof, withthe end of thescrew adapted to screw down upon the lower leaf and forcethe latter down onto the said slides. 'Ihe lower leaf of this clip 32 iswaved or sinuous,Y as indicated at 32a in Figure 3, so that the lowerleaf immediately under the end of the screw will press primarily uponthe central slide I4, for locking that slide against longitudinalmovement, while the lateral slides I3 and I5 may still be so moved.Another boss 33 is freely seated forwardly on the center slide I4, thebase thereof being ared laterally to overlap the lateral slides I3 andI5, this boss being locked against rotary movement by a marginal teat33a depended from its under face into a pin-hole 34 ,formed in the slideI4. The boss 33 and the slide I4 are tapped perpendicularly down throughto receive a knurled thumb screw 35 formed with a shoulder 35a below theknurled head. By turning down the screw 35 until the shoulder strikesthe boss, the flared basal margins of the boss overlapping the lateralslides, are forced upon those slides, thus locking the three slides I3,I4, I5, together to move as a unit. rThe under face of the boss 33 isconcaved to form lateral feet 3317, adapted to firmly engage the lateralslides, for releasably locking them all together to move as a unit inthe lateral guide rails l.

In use, the screws 3|, 35 are loosened and the slide I3 is drawn outabout one-half inch. Slide I4 is drawn out or back full length and slideI5 is pushed fully in or forwardly. The strike plate 24 is then laidupon the forward end of the gauge, with its back edge snug against thestoplip I, with the bolt opening 24a over the work lug I8 on the slide|3. Then push the slide'I4 in forwardly, pressing work lug I9 rmlyagainst n the front edge of the strike plate. Then tighten the screw 3|,and pull out the slide I3 until work lug I8 is snug against the outermargin of bolt opening 24a of the strike plate. The work-lug 20 of slideI5 will now be snug against the back edge of the strike plate. Nowtighten the screw 35, thus locking the three slides together. Thescribing points 22, 23, are now set to mark or cut on the door jamb theexact width of the strike plate. Then loosen the screw 3|, pull out thethree slides together and remove the strike plate. Then place the corner9a of the gauge against the free margin of the door, at the closing orstop side thereof and across the lock bolt 29. Then push the slide barsinward to bring the work lug 26 up against the outer, flat side of thebolt and tighten the screw 3|. Next locate the height of the strikeplate on the door jainb 25 and make pencil marks at top and bottom ofthe plate and plate lug 24h. Then holdthe stop lip I0 rmly against thestop 25a of the door jamb and look through the opening between slidesI4, I5 to locate pencil marks. Then press the gauge against the jamb sothat the scribing points` 22, 23, will mark the lateral limits of thestrike plate on the door jamb. A chisel can Ythen be used to recess thejamb for fully seating the plate, if desired that the plate be so inset.

While I have shown and described a certain embodiment of the inventionand specific structural features thereof, any desired changes,alterations or additions may be made, within the scope of the claim.

I claim:

In a device of the kind described, an oblong base plate turned up at itsends to form lips at the front and rear ends thereof, the rear lip beingslotted along its base, parallel guide rails on the lateral margins ofthe upper side of the base plate, the said plate being formed with anelongate work slot adjacent one guide rail and opening out through thelip and the forward end of the plate, three elongated gauge slidesinserted through the slot of the rear lip for independent slidablemovement within the space between the guide rails, work lugs seatedinthe upper sides of the forward ends of the three slides, the two lugsimmediately at the said work slot being oifset toward one another tomutually overlap these two slides,.scribe lugs seated in the under sidesofthe forward ends of the slides at the Work slot, and offset vto workin longitudinal alignment through said slot, a two-way work lug vrigidlyandperpendicularly mounted at the rear vend of the lateral slide remotefrom the work slot, means for releasably locking thethree slides to movein unison relative to the base plate, and separate means for releasablylocking the center Yslide against movement relative to the base plate.

' JACOB M. JOHNSON.

